Airplane



H. A. HICKS June 16, 1931.

AIRPLANE Filed May 6. 1930 ATTORNEY.

Patented June. 16,1931;

ELROLDA. HIGK S, OI DETROIT, IIGHIGAJT, DEABBOBN, MICHIGAN, A ,00

E2NT OFFICE.

sssrenon. 'ro roan Moron consumer aromrron or nmwnnn AIRPLANE The object of my invention is to provide an airplane having 1 an adjustable landing gear whereby the position of the plane relative to the ground may be varied.

5 A further object of my invention is to provide an adjustable landinggear of the class described which may be conveniently operated b This device is primarily adapted for large.

airplanes of the transport type. The fuselage of such airplanes have relatively lari ground clearances when in a position for ta ing-01f or landing so that a portable ladder or gan'gplank must be provided for the pas-" sengers when entering or leaving the plane.

In my improved'construction the fuselage of the ship'may be lowered so that it is just barely above the ground thereby making 1t very convenient for the passengers to enter or leave the plane. It will be understood that the minimum ground clearance for planes of this type is from four to six feet which makes the'entering or exit ofpassengers diflicult.

With this device the minimum ground clearance is maintained when theplane is takingofi or landing, the fuselage being lowered practically to the ground just before the piissengers are about to enter or leave the p ane. I A further p ose of this invention is to provide .meansw ereby .the overall height of the plane may be reducedso that it may-be stored in existin hangarbuildings in w -'chordinarily the P am couldnot enter.

Transport lanes of the type herein shown- I; are provid with motors and propellersplaoed above the mainwin so that then: total height'sometimes ex s thehe ight of the ordin hangar doors. The airplane hangars u in connection with most of the largeair lines, includin the TranecontmentalAir Transport an the National Transport, are equipped with standardized doors having a clearance of slightly less than twenty feet in height. This clearance is ample for the moderate size planes now. used but'is notfsuflicient to aiccommodatbegthe 'lar ert o p anes now- In pro ducemThese larger planes .althoug P 3 gfeaturee very des rable for use on I the pilot from the airplanes cockpit.

- shock absorber is provided which normally invention consists in the arrangement, con- .struction, and combination .of the venous Application fled m 6, 1930. serial No. 450,148. I

feet when in its taxiing position bu this height is reduced to. about nineteel i feet when my landing-gear is raised thereby allowing this plane .to doors. I accomplish this desired result by roviding a telescopic landing gear strut w ich enter twenty-foot hangar consists'generally of a pistbn and, cylinder, a v

for the landing gear. The iston is held in its extended osition by a r pressure controlled from t e ilots cockpit. When it is desired to lower t e ship the air pressure in the. cylinder is reduced so that the strut ually shortens. Due'to the natural on 'on-' ing of this pneumatic device, an excellent which strut normally acts as g? shock absorber operates through a range'of about one uar-. ter of the total movement of the mem rs. However, if forced. landings are to be made on rough ground the airpressure in the cylinder may be-reduced so that a very flexible landing gear is provided to thereby absorb the mpacts encountered when landing.

With these and other objects in view my parts of my improved device, as described in I 'the specification, claimed in my claim, and

illustrated in the accompanying drawings, in which: 7 v

Figure 1 shows a front elevation of an airplane: constructed in accordance with this invention. c

Figure 2 shows a side elevation of the plane shown in Figure 1, the. device being illustrated in its lowered position by dotted lines.

Figure 3 shows a sectional view throng the shock absorbing element, and" Figure 4 shows an enlarged view of the replane is provided with a single wing 11 ex-- tending from each side of the fuselage, a rudder 12, and control surfaces 13. I have provided a plurality of motors 14 mounted above the upper surface of the wing 11 to propel the plane in the conventional manner.

T e rear end of the fusela e 10 is provided with a tail wheel 15 while e forward portion thereof is supported on my improved landing gear. Diagonal struts 16 extend from the lower corners of the fusela e up to the under side of the wing and axle s a-fts 17 are pivotally connected to the fuselage ad-- jacent to the fittings connecting the struts 16, which axles are provided with landing wheels 18 rotatably mounted on the outer ends thereof. Myeimproved shock absorber ton 23 is secured thereto which 0 elements extend tween the outer ends of the struts 16 and the axles 17 so that the pivotal movement of these axles will be accompanied by the telescoping of the shock absorbing members. Braces 19 extend from the wheels 18 to the rear portions of the wing 11 to which they are pivotally connected to support they landin gear when the brakes are applied to the w eels 1'8.

The shock absorber assemblies extending between the wheels 18 and the up r ends of the struts 16 each consist of'a tu ular housing 20 having a ca 36 secured over its upper end which cap is plvotally' secured to the upper end of the strut 16. A sleeve 21 is reciprocall mounted in this housin the lower end 0 which is pivotally secur to the axle 17 adjacent .to the wheel 18. A rod 22 is fixedly secured within the cap 36 and extends downwardly into the sleeve 21 where the pisrates within the bore of the sleeve 21. e upper end of the sleeve 21 within the housing 20 is provided with a ring sha edpiston 24 which coacts with the bore in t e housing 20. It-may 6 thus be seen that when the sleeve 21 is forced into the housing 20 compression'of the fluid within the two sleeves resists this force.

I have provided a fitting 25 screwed into the upper part of the housing 20 which con,-

nects with a valve 26 and pipe line 27. The plpe line 27 extends up through the wing 11 and into the fuselage 10 where it connects with an air reservoir or tank 28 which reser voir is supplied from an air pump 29 driven direct from one of the airplane engines. An air gauge 30 is rovided in connection with the tank 28 so t at the pressure in this tank may readily be known to the'pilotr I have provided the valve 26 adjacent'to the housing 20 to guard ainst the results otherwise caused 1f the tu 27 should burst. Remote sleeve 21 from the housing control apparatus is provided for operating these valves from the pilots coc it so that the plane may be controlled entirely from within.

When the airplane is in its,lowered' osition, as illustrated by dotted lines 31 in igure 2, the sleeve 21 is fully inserted in the housing 20. However, when the pilot operates ,the valves 26 the air under pressure in the reservoir 28 enters above the piston 24 thereby adually forcin the sleeve 21 from the housing so that the p ane rises to the sition shown by solid lines in the above 2- ure. The pneumatic pressure within the housing 20, of course, formsa resilient cushionin device so that as the plane takes-ofi the w eels 18 are allowed a considerable vertical movement to compensate for irregularities in the field.

It will be apparent that when the plane is in its lowered position its overall height will bematerially decreased and that the doorway 37 of the-fuselage will be lowered to a position so that passengers -may enter or sleeve 21 is filled with oil so that as this sleeve is compressed into the housing 20 the oil therein will be forced through the ports 32. A conical shaped valve 33 is reciprocally mounted on the rod 22'above the piston 23 and a spring 34 urges this valve into contact with the top of the piston so asto revent the backinto the sleeve 21. I

From the foregoing it may-be seen that when the sleeve 21 is compressed into the hou 20 the oil therein will be forcedup one side of this piston to the other. The

flow of oil from the upper end 0 the piston throug the. ports 32 thereby forcing the valve 33 u wardly ainst the spring pressure 34. Ilittle or nz resistance is offered by the oil in this direction of movement-so that practically all of the compresfion p is resisted b the air pressure the housing 20. owever, when the rebound action occurs, the attempted withdrawal of the 20 is resisted by tle action ofthe valve 33 closing the ports 3 v I have provided bleader ports 35 thr the 'valve33 which allows a small quantity of oil to flow through this valve member. The sleeve 21-can only be withdrawn from the housi 20 in... roportion to the oil flowing throug these leader ports-so that the revented.

lab

7 Among the many advantages arising from the use of my improved device it may be well to mention that planes e uipt with b my landing gear may be convenien y lowered so that passengers can enter or leave the plane without the use orig planks, portable ladders or the like. i tier, the plane may be lowered so that large shigi may enter through existing hangar doors w ch previousl were barriers for such size of planes. till a further feature resulting from the use of this device is that the air pressure in the shock absorber may be adjusted so that in case of a forced landing exceptional resiliency is obtained to protect the plane against damage.

Some changes may be made in the arrangement, constructiom'and combination of the various parts of my improved device without departin from the spirit of my invention, and it IS my intention to cover b my claim, such changes as may reasonab y be included within the scope thereof.

I claim as my invention:

In an airplane constructioma fuselage, a

v landing gear, telescopic shock absorbers supporting said fuselage on the landing gear,

said shock absorbers havin hydraulic means for checking the rebound o thelanding gear and pneumatic means resisting thecompression thereof, and an auxiliary source of compressed air under-the control of the pilot while operatingthe airplane for varying said pneumatic compression resistance, whereby the pilot may vary the operatincfi stroke of k the shock absorber to suit the aracter or the landing field;

mom) A. HICKS. 

